/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated January 1, 2020. Replaces all prior versions.
 *
 * Copyright (c) 2013-2020, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
 * conditions of Section 2 of the Spine Editor License Agreement:
 * http://esotericsoftware.com/spine-editor-license
 *
 * Otherwise, it is permitted to integrate the Spine Runtimes into software
 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
 * Spine Editor license and redistribution of the Products in any form must
 * include this license and copyright notice.
 *
 * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
 * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

using UnityEngine;

namespace Spine.Unity
{

    /// <summary>
    /// Add this component to a SkeletonMecanim GameObject
    /// to turn motion of a selected root bone into Transform or RigidBody motion.
    /// Local bone translation movement is used as motion.
    /// All top-level bones of the skeleton are moved to compensate the root
    /// motion bone location, keeping the distance relationship between bones intact.
    /// </summary>
    /// <remarks>
    /// Only compatible with <c>SkeletonMecanim</c>.
    /// For <c>SkeletonAnimation</c> or <c>SkeletonGraphic</c> please use
    /// <see cref="SkeletonRootMotion">SkeletonRootMotion</see> instead.
    /// </remarks>
    [HelpURL("http://esotericsoftware.com/spine-unity#SkeletonMecanimRootMotion")]
    public class SkeletonMecanimRootMotion : SkeletonRootMotionBase
    {
        #region Inspector
        const int DefaultMecanimLayerFlags = -1;
        public int mecanimLayerFlags = DefaultMecanimLayerFlags;
        #endregion

        protected Vector2 movementDelta;

        SkeletonMecanim skeletonMecanim;
        public SkeletonMecanim SkeletonMecanim
        {
            get
            {
                return skeletonMecanim ? skeletonMecanim : skeletonMecanim = GetComponent<SkeletonMecanim>();
            }
        }

        public override Vector2 GetRemainingRootMotion(int layerIndex)
        {
            var pair = skeletonMecanim.Translator.GetActiveAnimationAndTime(layerIndex);
            var animation = pair.Key;
            var time = pair.Value;
            if (animation == null)
                return Vector2.zero;

            float start = time;
            float end = animation.duration;
            return GetAnimationRootMotion(start, end, animation);
        }

        public override RootMotionInfo GetRootMotionInfo(int layerIndex)
        {
            var pair = skeletonMecanim.Translator.GetActiveAnimationAndTime(layerIndex);
            var animation = pair.Key;
            var time = pair.Value;
            if (animation == null)
                return new RootMotionInfo();
            return GetAnimationRootMotionInfo(animation, time);
        }

        protected override void Reset()
        {
            base.Reset();
            mecanimLayerFlags = DefaultMecanimLayerFlags;
        }

        protected override void Start()
        {
            base.Start();
            skeletonMecanim = GetComponent<SkeletonMecanim>();
            if (skeletonMecanim)
            {
                skeletonMecanim.Translator.OnClipApplied -= OnClipApplied;
                skeletonMecanim.Translator.OnClipApplied += OnClipApplied;
            }
        }

        void OnClipApplied(Spine.Animation animation, int layerIndex, float weight,
                float time, float lastTime, bool playsBackward)
        {

            if (((mecanimLayerFlags & 1 << layerIndex) == 0) || weight == 0)
                return;

            if (!playsBackward)
            {
                movementDelta += weight * GetAnimationRootMotion(lastTime, time, animation);
            }
            else
            {
                movementDelta -= weight * GetAnimationRootMotion(time, lastTime, animation);
            }
        }

        protected override Vector2 CalculateAnimationsMovementDelta()
        {
            // Note: movement delta is not gather after animation but
            // in OnClipApplied after every applied animation.
            Vector2 result = movementDelta;
            movementDelta = Vector2.zero;
            return result;
        }
    }
}
